Copper-oxide catalyst



Patented Sept. 7, 1954 UNITED STATES PATENT OFFICE 2,688,603 COPPER-OXIDE CATALYST Maynard M. Baldwin, Columbus, Ohio, assignor, by mesne assignments, to Mathieson Chemical Corporation, Baltimore, Md., a corporation of Virginia No Drawing. Application April 24, 1948, Serial No. 23,131

3 Claims. (Cl- 252476) This invention relates to a catalyst and to a nium, vanadium, chromium, manganese, iron, cumethod of preparing this catalyst, as well as to a balt, nickel, copper, zinc, yttrium, zirconium, novel method of catalyzing the oxidation of olecolumbium molybdenum masurium, ruthenium, fins which employs this new catalyst. rhodium, palladium, silver, cadmiu ,lanthanum, The preparation of catalysts by the deposition 5 hafnium, tantalum, tungsten, rhenium, osmium, of metals or metal compounds on refractory mairidium, platinum, gold, mercury, actinum, thoterials, known as supports, is common in the art. rium and uranium. However, no significant attention has been given, Taking the metal copper as an example, comin the preparation of catalysts of this type, to the pounds which may be used as suitable precursors use of particular types of compounds and use of include copper phthalocyanine, copper hydroxythese compounds at low concentrations on the quinoline, copper complex of bis-acetoacetonylsupports to improve the efficiency and specificity ethylenediamine, copper caproate, copper Z-ethof the catalysts. ylhexoate, copper stearate, copper salt of uric It is a primary object of this invention, thereacid, copper bonzoate, copper diphenate, copper fore, to provide a catalyst having superior activquinolate, copper salts of amino sulfonic acid ity, improved stability of activity, and improved such 4-aminoto1uene-3-sulfonate and copper specificity. 2-amino-5-naphthol-7-sulfonate, copper amino Another object of this invention is to provide acetate, copper amino benzoate, copper resinate, a catalyst capable of catalyzing the oxidation copper salts of acids such as adipic, azelaic, acoof olefins. Still another object of this invention nitic and aurin tricarboxylic acid, and their comis to provide a catalyst having good stability at plexes with ethylenediamine.

relatively high temperatures. This list of compounds 15 not exhaustive, and Other objects and advantages of the present insimilar or comparable compounds including the vention will become apparent to those skilled in other metals of the named class may be emthe art from the detailed description thereof as ployed. For example, suitable precursors may set forth hereinafter. be obtained from the 8-hydroxyquinoline com- It has been discovered that a highly active cataplexes with scandium, titanium, vanadium, chrolyst capable of promoting both difficult and demium, manganese, iron, cobalt, nickel, copper, sirable chemical reactions can be made by diszinc, yttrium zirconium, columbium, molybtributing an organic compound having a large denum ruthenium, rhodium, lead, silver, cadmolecular volume and containing a potentially mium, lanthanum, hafnium, tantalum, tungcatalytically active metal over the surface of a stem, gold, mercury, actinum, thorium, palladium, suitable support, and decomposing this precursor and uranium. The copper cobalt, manganese, to remove the organic portion of the molecule. iron, cadmium, lead, and nickel salts, of the The novel results obtained by the catalyst comnaphthenic acids may also be employed, prising the present invention are believed to be Further examples of suitable precursors are due to the size (volume) of the precursor molebis-dimethyl glyoxime cobalto chloride; lancule and also to the relative isolation of the metal thanum hexa-antipyrine iodide; dipyridyl peratom within the precursor from other metal rhenate; nitron complex with rhenium; benzi-- atoms. Organic metallic compounds which are dene complex of osmium; dibenzyl mercury; disuitable as precursors are those in which each phenyl mercury; phenyl mercury propionate;

metal atom is chemically combined with at least anthranilates of zinc, cobalt, nickel, cadmium, two Or anic roups eac containing foul of more manganese, copper, lead and mercury; the thonon-metallic atoms in a chain or cyclic structure. m d l d alts of picrolonic acid; nickel and The metal which constitutes a portion of the lead dimethylglyoximes; copper, cadmium, zinc, precursor must, of course, be capable of catalytic uranium, lead, silver, manganese, nickel, cobalt, activity. Metals which are characterized by catairon, chromium and titanium salts of quinaldinic lyti p p a mm y a fi d a those acid; salicylaldoxine of copper and platinum; metals which possess at least one differentiating cupferone complex of iron copper, zinc, thorielectron in the second from the outermost shell, 5 um, tantalum, and vanadium; mercaptobenzthior penultimate shell. Such a classification is azol complex of gold; dithizon complexes of copset forth, for example, in the patent to Huffman, per, mercury, cobalt, zinc, nickel, cadmium, man- No. 2,437,533, issued March 9, 1948. The class ganese, iron, lead, palladium, and platinum; in of metals having their difierentiating electronsin addition to complexes of almost all of these the penultimate shell includes scandium, titametals with naphthaquinonedioxime.

radicals both secondary valence bonds.

The present invention is concerned with the feet of that support upon the catalyticaction of the catalyst. Consequently, any of the more commonly used supports which are widely known in the field of various clays. been obtained, supports. Pumice has proven to be particularly satisfactory.

material.

After the precursor has been applied in a thin layer to the surface of the support, the precursorcoated support is heated is exactly the chemical composition of the residue.

For example, these catalysts are suitable for catalyzing the oxidation of compounds such as the olefins, aralkyls,

' dehydrogena- More specifically, these catalysts acrolein from propylene, and methacrolein from isobutylene.

In order to more clearly set forth the present invention and to the art to practice the same, the following degrams of free copper.

The optimum for synpropylene is 325 0., whereas the optimum for the synthesis of methacrolein from isobutylene is about 380 C.

, most generally accepted theory of catalysis is that there exists a multitude of active centers on each catalyst which are sources of activation energy for the chemical reactants that are absorbed and desorbed at these points to effect the desired reactions. It is believed that these active centers consist of a somewhat different crystal formation from the surrounding material and therefore have the peculiar characteristic of absorption and desorption so vital in catalysis. The activity of a catalyst is determined by the number of active centers per weight or per volume of catalyst.

In the present invention the metal in the precursor is surrounded by organic radicals. The precursor is then spread thinly over a support surface and decomposed, leaving relatively isolated deposits of metal or metal oxides upon the Because of the extremely high state of division of the metal in cursor, sometimes approaching molecular division, a much greater surface area per weight of obtained. Consequently, there is a greater surface upon which active centers may occur. Also because of the relative isolation of the metal molecule, there is a greater probability of their being in the active state.

This theory is borne out by actual observations. As above stated, catalysts comprising the present invention are more active than catalysts of the 'prior art. Furthermore, high temperatures have little effect on these catalysts. This can be exfact that because of their relative there can not be melting together of adjacent metal deposits so as to destroy active centers by sintering. In addition, the isolation of the metal deposits as shown by the fact that the small molecules, such as copper nitrate which do not afford opportunity for isolation of the metal, do not have the increased activity of these larger molecules. Furthermore, it has been found that higher concentrations of the precursor on the surface of the support decrease the activity of the catalyst rather than increase it. In terms of the above set forth theory, this means that too high concentrations of the precursor cause overlapping deposits cf metal residue and thus decrease the probability of formation of the active centers which otherwise would increase the catalytic ac tion.

It is apparent from the above description isolation that the present invention relates to a catalyst composed of a support and a residue formed in situ upon a support by decomposition thereon of a layer of an organic compound which contains a metal having its diiferentiating electron in the penultimate shel, and which is least two organic groups each having four or more non-metallic atoms in a chain or cyclic structure.

attached to at within the scope of this invention are organic groups than at the Included precursors in which the above may be interconnected otherwise metal. This catalyst is advantageous in that it is more active and makes possible new syntheses. Furthermore, this catalyst is active longer than the catalysts of the prior art. In addition, catalysts of the present invention are not effected. by high temperatures, so that reactions may be run at a faster rate than heretofore. The extremely good yield obtained with these catalysts makes possible commercialization of processes heretofore thought impossible.

What is claimed is:

1. A catalyst prepared by thinly distributing over the surface of a support copper phthalocyanine, and heating the thus coated support in the presence of oxygen until the corresponding oxide of copper is formed, thereby effecting the removal of the organic portion thereof.

2. The method of making a catalyst which comprises the steps of preparing an dispersed mixture of copper phthalocyanine in a liquid medium, immersing a support material in said mixture, removing and drying material to provide a thin layer of 'said copper phthalocyanine, and heating said layer of copper phthalocyanine until the corresponding oxide of copper is formed, thereby removing the organic portion thereof.

3. A method of preparing a catalyst which comprises the steps of preparing an intimately dispersed mixture of copper phthalocyanine in a liquid medium, applying a thin layer of said mixture to a suitable support material, and heating said layer of said mixture in the presence of oxygen until the copper phthalocyanine is changed to the corresponding oxide of copper.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,782,857 Miller et al Nov. 25, 1930 1,896,320 Luft Feb. 7, 1933 1,937,728 Storch Dec. 5, 1933 2,040,782 Van Peski May 12, 1936 2,118,001 Andrews May 1, 1938 2,211,208 Ipatieff et al. Aug. 13, 1940 2,257,157 Connolly Sept. 30, 1941 2,383,711 Clark et al. Aug. 28, 1945 2,383,372 Stewart Nov. 6, 1945 2,402,440 Owen June 18, 1946 2,421,361 Toussaint et a May 27, 1947 2,451,485 Hearne et al Oct. 19, 1948 2,490,260 Ehrhardt Dec. 6, 1949 

2. THE METHOD OF MAKING A CATALYST WHICH COMPRISES THE STEPS OF PREPARING AN INTIMATELY DISPERSED MIXTURE OF COPPER PHTHALOCYANINE IN A LIQUID MEDIUM, IMMERSING A SUPPORT MATERIAL IN SAID MIXTURE, REMOVING AND DRYING THE SUPPORT MATERIAL TO PROVIDE A THIN LAYER OF SAID COPPER PHTHALOCYANINE, AND HEATING SAID LAYER OF COPPER PHTHALOCYANINE UNTIL THE CORRESPONDING OXIDE OF COPPER IS FORMED, THEREBY REMOVING THE ORGANIC PORTION THEREOF. 